an adjective used to describe someone who is visually disturbing, ugly, and/or nasty.
origin: at the site of a "sour" person, you make a "sour" face, as such when you suck a lemon.
The act of alienating and or disheveling others to better oneself. There are many ways to go sour, including: acting a fool in front of the opposite sex, blatant disregard for your friends' feelings, and flagrant self-centerdness.